Method of making resilient filter elements and batts



June 15, 1954 J. B. SEBOK ETAL 2,680,899

METHOD OF MAKING RESILIENT FILTER ELEMENTS AND BATTS Filed May 7, 19'48 6 Sheets-Sheet l W I fHZ EH furs afose vh B. 56506; Cfi FIM Sebok 53 J25 iwl mmg June 15, 1954 J. B. SEBOK ET AL METHOD OF MAKING RESILIENT FILTER ELEMENTS AND BATTS 6 Sheets-Sheet 2 Filed May 7, 1948 [Hz E1? 277. 5

J 15, 19 4 J. B. SEBOK ET AL 2,680,399

METHOD OF MAKING RESILIENT FILTER ELEMENTS AND BATTS Filed May 7, 1948 6 Sheets-Sheet 3 2Z 3 l I a e e 0 Fra /2 Saba/2 j $5.2m W wg/5 TTS June 15, 1954 J. B. SEBOK ETAL METHOD OF MAKING RESILIENT FILTER ELEMENTS AND BA 6 Sheets-Sheet 4 Filed May 7, 1948 .fnrenfars cfoseyvh $860k qi Frank Seboh by fiflgs TTS June I5, 1954 J. B. SEBOK ETAL METHOD OF MAKING RESIL IENT FILTER ELEMENTS AND BA 6 Sheets-Sheet 5 Filed May '7, 1948 1571 5 17 furs Josqpk B. Saba/26$ Fran ii Seboh by 7 II I TTS June 15, 1954 J. B. SQEBOK ETAL METHOD OF MAKING RESILIENT FILTER ELEMENTS AND BA 6 Sheets-Sheet 6 Filed May 7, 1948 fnz enfor's (Joseyv/z B. Saba/z Fran/ i $627012 @Z w afmfii s Patentecl June 15, 1954 METHOD OF MAKING RESILIENT FILTER ELEMENTS AND BATTS Joseph B. Sebok and Frank Sebok, Detroit, Mich.,

assignors to Houdaille-Hershey Corporation, Detroit, Mich, a corporation of Michigan Application May 7, 1948, Serial No. 25,726

4 Claims.

This invention relates to improvements in a method of making resilient filter elements and batts, and more particularly to a method of making filter elements and filter units for use in automotive air cleaners, although the invention may have other uses and purposes as will be apparent to one skilled in the art.

For purposes of clarity, the instant invention will be described mainly in connection with the manufacture of filter elements and filter units for automotive air cleaners; that is, filter elements and filter units used in air cleaners for association with the carburetor air intake of internal combustion engines. As these units and elements have been manufactured in the past, they were very objectionably expensive and added considerably to the cost of an air cleaner, especially because the casing structure of an air cleaner is substantially essential as to material, shaping, finishing, etc., and only a very minor saving may be acquired by variation in that casing. On the other hand, if the cost of the filter element may be reduced without the sacrifice of efilciency, without endangering pullover of cleansing liquid in the carburetor of the engine, and without increasing the restriction to air flow through the cleaner, such saving is very substantial in the overall cost of the cleaner.

One of the prime objects of the instant invention therefore is to provide a method of making such a filter element and filter unit in an extremely economical manner and of economical material, and yet provide a better and more durable unit and a more satisfactory unit overall than has heretofore been produced.

It is still another object of this invention to provide a new and novel method of making a filter element or resilient batt from short animal hair such as hog hair, in which method the hair is simultaneously fiameproofed and freed of any static electricity,

Still another object of the invention resides in the provision of a new and novel method of making a filter element or resilient batt from relatively short animal hair, such as hog hair, wherein the strands of hair are bonded together with a suitable plastic bonding agent which is applied to the strand by a dipping process.

It is a further object of the invention to provide a new and novel method of making a complete filter unit for an automotive air cleaner.

Further, it is an object of the invention to provide a new an novel method of making a resilient self-sustaining batt from bonded animal hair, such as hog hair, and of indefinite length.

The individual filter element and unit or batt, considered as a product or article of manufacture, is more specifically set forth, described, and claimed in a Joseph B. Sebok copending application for patent entitled Filter Unit and Resilient Filter Element or Batt, filed March 20, 1948, Serial No. 16,078, now issued in Patent No. 2,582,915.

The machine set forth herein to better explain the method is more fully set forth, described, and claimed in our divisional application entitled Machine for Making Resilient Filter Elements and Batts, filed December 20, 1950, Serial No. 201,728.

While some of the more salient features, characteristics and advantages of the instant invention have been above pointed out, others will become apparent from the following disclosures, taken in conjunction with the accompanying drawings, in which Figure l is a front elevational view of a machine embodying principles of the instant invention;

Figure 2 is a vertical sectional view of the structure of Fig. 1, taken substantially as indicated by the line IIII of Fig. 1, looking in the direction of the arrows, and in effect providing a side elevational view of the machine;

Figure 3 is a top plan view of the machine;

Figure 4 is a fragmentary plan sectional View through the discharge end of the rollers and belts arrangement with parts shown in elevation, and taken substantially as indicated by the line IV-IV of Fig. 2;

Figure 5 is a view similar in character to Fig. 4, but taken on a lower plane as indicated by the line V-V of Fig. 2, illustrating the comb arrangement of the machine;

Figure 6 is a fragmentary enlarged and substantially central vertical sectional view through the upper portion of the machine taken substantially as indicated by the line VIVI of Fig. 1;

Figure 7 is a fragmentary enlarged substantially central vertical sectional view of the lower portion of the machine taken substantially as indicated by the line VII-VII of Fig. 1;

Figure 8 is an enlarged bottom plan view of the filter holding shell in which the filter unit is formed;

Figure 9 is a central vertical sectional view illustrating the clipping of the filter unit undergoing formation in a bath of plastic bonding material;

Figure 10 is a view similar in character to Fig. 9 il ustrat ng the complete f lter unit being W thdrawn from the bath of plastic bonding material;

Figure 11 is a diagrammatic, part sectional and part elevational view illustrating in general the process of making continuously a self-sustaining resilient batt of indefinite length; and

Figure 12 is a fragmentary pictorial illustration of the resultant batt made as indicated in Fig. 11.

As shown on the drawings:

A product, such as a filter element or unit for an air cleaner, or a resilient batt, made by the machine and under the method embodied in the instant invention, may easily and economically be formed from short animal hair such as rabbit fur, horse hair, hair from the body of a cow or similar animal, but preferably from hog hair, a product having an extremely limited use prior to the advent of this invention. Applicants know of no instance in which hog hair was ever used I as a filter element, especially for cleaners. Cattle tail hair has been used for this purpose heretofore but that hair is of consider able length and requires special treatment before it can be used. Further, the resultant cattle tail hair filter element is not as satisfactory or endurable as one made of hog hair under the instant invention.

It makes no difference whether summer or winter hair is used, the average variation in length being approximately three -eighths of an inch, and that variation is not sufficient to warrant any special attention.

in the general practice of the method here involved, the hog hair is talren substantially as it comes from the packing plant or other source.

t is preferable at the start to run the hair through a gin mill or the equivalent to either eliminate or pulverize toe nails and the like so as to either avoid injury to the apparatus or prevent the production of a defective element. The hair is then taken in relatively large quantities and dunked or dipped in a bath of flameproofing liquid, which may be a 15 to solution by weight of ammonium sulfamide in water. Ample time for this flameproofing operation is live minutes. This operation not only flameproofs the hair, and this is required in some cases for a filter element for an automotive air cleaner, but it also accomplishes another highly important result, the hair. If the static electricity were permitted to remain, it would be extremely difficult if not impossible to get an even distribution of the hair later when the filter element is formed. It is true that a water bath would remove the static electricity of the hair, but since a bath is necessary, it is just as easy to effect the fiameproofing operation at the same time.

After the flameproofing and static removing operation, the hair is driedin any suitable manner. Air drying is satisfactory, but the drying may be hastened if so desired by the application of heat or a blast of hot air.

When individual filters are made, and the instant machine is disclosed and described as making one filter at a time, for purposes of clarity, the material is then weighed out into bunches of a specified weight. For certain types of air cleaners, 59 gram bunches of hair are satisfactory with a tolerance factor of minus nothing to plus 5 grams. This bunch of hair is then passed through the machine, and the machine after separating the hair fibers, removing the dust and scales, deposits the hair evenly and uniformly directly into the holding shell of the filter unit.

automotive air namely, removing static electricity from V withdrawn from the dipping the upper rolls 8- and I l Preferably a slightly upwardly bowed tamper may be gently used after the holder has been filled with hair, but the use of the tamper is not essential.

After the deposition of the predetermined amount of hair into the holding shell, the entire structure is dipped in a solution of a plastic bondingagent. Such agent bonds the fibers to each other at random and at irregular intervals, and likewise bonds the entire mass of hair directly in and to the holding shell, which shell is preferably of metal. In the bottom of the shell a protective screen may be provided, and heretofore it was necessary to spot-weld that protective screen to every radial rib in the bottom of the shell, but with the bonding agent the protective screen is firmly held in position by the filter element.

For bonding purposes, an oil resistant rubber substitute bonding agent, such as neoprene latex, may be used, and the solution of 25% solids and water is satisfactory for this purpose. The neoprene latex may be cured or set by heat treatment at 250 F. for 2 to 5 minutes, by way of example. Of course, once set, the bonding agent is not thereafter soluble in water and is substantially of a permanent character.

A vinyl solution may also be utilized for this purpose and one satisfactory example of such a solution includes 15% vinyl polymer or copolymer, 15% methyl ethyl ketone, and 70% commercial toluol. That solution may then be made into an even mix with a half portion of the solution and a half portion of toluene, into which the filter unit may be dipped. The speed of removal from the clipping bath obviously affects the resultant density of the filter element. If it is withdrawn from the dipping bath with great rapidity, it will be denser, of less height, than if it is gently bath.

After the dipping process, the unit may be either air dried or heat treated as explained above. Even in air, 15 minutes is ample to effectively set the plastic.

In the illustrated embodiment of the machine there is shown a suitable frame i made of any suitable material such as angle iron, and with a pair of platforms 2 and 3 (Fig. 3) on top. A box-like housing 6 is also mounted on top of the frame, substantially centrally of the forward side thereof, and the front plate of this housing has been left removed so as to provide both better vision of and access to the mechanism inside the housing. As seen best in Fig. 6, the rear wall of the housing is provided with a relatively large aperture or opening 55 therein.

With reference again to Fig. 6, it will be seen that inside the housing there is a lower roll 6 carried on a shaft l and an upper roll 3 carried on a shaft 9, over which rolls an endless belt it travels. The upper roll 8 is urged away from the roll 6 by means of a suitable spring biasing mechanism H on each side of the housing t to maintain tension on the belt. Another pair of rolls including a lower roll i2 on a shaft i3 and an upper roll I l on a shaft i5 carry a second belt It, which belt carries a chain H on the inside secured to the belt in any suitable manner as by one or more rivets It. The rolls l2 and I4 are notched as indicated at ill in Fig. 6' to accommodate such chain.

As is clearly apparent from the showing in Figs. 3 and 6, the lower rolls 6 and 12 are disposed immediately adjacent each other, while 4 are spread apart so that the inside reaches of the belts l and I6 form a relatively large V-shaped pocket extending the full width of the housing 4. The lower roll I2 is biased inwardly so as to establish tight contact between the belts at the apex of the V pocket by means of suitable spring biasing elements on each side of the housing. It is important that the belts be maintained in close contact with each other at the apex of the V pocket.

As is seen best from the showing in Fig. 3 the roll 6 is driven from a fractional horsepower motor 2i mounted on the platform 2 through a double set of speed reducers 22 and 23 and a shaft 25. A satisfactory operating speed for the roll 6 is nine revolutions per minute. The drive is transferred from the roll 6 to the upper roll associated with the forward belt by means of a gear train on the opposite side of the housing. The gear train, best seen in Fig. 2, includes a gear 25 on the shaft i of the roll 6, a gear 26 of the same size on the shaft [5 of the roll l4, and a pair of like gears 27 disposed therebetween and mounted on suitable stub shafts. Thus, the roll is and the belt It is driven at the same speed as the roll 8. Both belts are therefore positively driven, and the inside reaches of these belts travel downwardly as indicated by the arrows in Fig. 6.

With reference now to Figs. 5 and 6, it will be seen that beneath the apex of the V pocket formed by the belts, a rotary comb 28 is carried on a shaft 29. The comb extends the full width of the housing 4. Specifically, the comb comprises a roll with several spiral rows of pins 28a extending outwardly therefrom. This comb may be driven by a fractional horsepower motor 30 mounted on the platform 3 as seen clearly in Figs. 1 and 3. A satisfactory speed for this comb is in the neighborhood of 5000 revolutions per minute.

As the hair deposited in the V pocket between the belts I 0 and it emerges from the apex of the V, it is engaged by the rapidly spinning comb and the individual hair strands are separated and hurled downwardly through a discharge spout 3 I. As seen in Fig. 6, a forward flange 32 extends from the top of the spout inside the housing 5 to guide the hair into the spout. There is also a rear flange 33 provided which is turned backward in its upper portion to permit dust and scale whipped from the hair by the action of the comb to be discharged rearwardly through the opening 5 in the housing. The high speed of the comb will give the effect of a blower both for advancing the hair through the discharge spout 3i and also for discharging the dust and scale through the opening 5 in the housing.

The lower portion of the machine is best seen in Figs. 1, 2 and 7. A pair of side members 34-3l support a cross shaft 35 upon which a platform 36 may pivot, as indicated by the dotted lines in Fig. 2. On the rear of this platform a fractional horsepower electric motor 3! is mounted which, through a suitable worm and gear arrangement 38, drives a vertical shaft 39 journalled in a superstructure 4&3, as best seen in Fig. 7. The upper end of this shaft fixedly carries a filter unit supporting pan 4! which, of course, rotates with the shaft.

Everything on the the platform upon release of a latch member 42 (Figs. 1 and 3) which is actuated by a slide pin 43. A cross pin 44 (Fig. 2) limits the backward tilting movement of the platform and holds it level during operation of the machine.

platform 36 tilts along with of the shell over the ribs M.

pins 28a of this comb When it is desired to operate the machine, the" actual filter holding shell that is ultimately used in the complete air cleaner is placed upon the pan 4|. With reference more particularly to Figs. 7 and 8, it will be seen that this shell comprises a cup-like metallic formation including an outer cylindrical wall 45 having an outwardly fiared upper margin 46. The bottom of the shell includes a plurality of radially extending ribs 47 with relatively large apertures Ma therebetween to permit passage of air upwardly through the filter unit when in the air cleaner. In the illustrated instance the particular filter unit is of the type for use in a so-called hat type liquid bath air cleaner for association with a downdraft carburetor. Such an air cleaner has a center outlet passage for the clean air, and accordingly the filter shell is preferably provided with a center tube 48. This center tube 48 may be attached to the shell after the formation of the filter element from the hair, if so desired, but it facilitates matters to attach it to the shell previously to the formation of the hair element, and then after the element has been completed spin the upper margin outwardly to the dotted line position seen in Fig. 10. In the outer portion of the bottom thereof the shell is also provided with a plurality of relatively small apertures 49 to facilitate drainage of the plastic compound after the dipping operation.

When there is to be a central opening through the filter element, a plug 5%, of wood or any suitable material, is attached to the top of the shaft 39, and if the filter element is not to have an aperture therein, that plug may easily be eliminated. Before the reception of the hair by the filter shell, a cylindrical sleeve 5! is preferably snapped over the lip 45 of the shell by spring clamps 52 or in any equivalent manner, to hold the hair in position above the shell before that hair is bonded by the plastic.

From the showing in Fig. 8', it will be seen that where a protective screen is required, such a screen 53 may merely be laid in the bottom Formerly, this screen was spot welded to each of the ribs 41 and that operation, in the illustrated instance, would require twelve spot-welds. Those spotwelds are no longer necessary with the present invention, because the plastic bonding agent not only bonds the individual strands of hair together, but bonds the hair filter element directly to the inside of the shell and to the screen 53, thus holding the screen firmly in position.

During operation of the machine, the filter holding shell is first mounted in position, and the sleeve 5! placed thereupon. The motors 2|, 36 and 31 are then started, and a predetermined quantity of short animal hair, such as hog hair, is placed in the V pocket defined by the belts ii! and it. This hair is gradually discharged through the apex of the V pocket between the belts and as it emanates from the lower end of the pocket, the hair is whipped by the comb 28, the tines or separating the individual strands of hair, and acting as a blower to force these strands of hair downwardly through the discharge spout 3! directly into the spinning filter holding shell. At the same time the hair is forced downwardly through the chute 3i, dust and scale from the air is forcibly discharged rearwardly through the opening 5 in the back of the housing 4.

The predetermined quantity of hair passed between the belts will be distributed evenly and with the individual hair strands disposed at random in the form of a mass 54 inside the filter holding shell and partially within the sleeve 5| as seen clearly in Fig. 7. The individual strands of hair will be interlocked with each other to such an extent that when the full measured quantity of hair has been deposited, the platform 36 may be tilted forwardly as indicated by dotted lines in Fig. 2, and the shell and sleeve removed therefrom, and then the sleeve removed from the shell, with the mass 54- retaining its original shape. The mass will then have the appearance of the showing in Fig. 9.

After the shell together with the hair mass 54 is removed from the pan 4!, the entire structure is then dipped into the plastic bonding solution. This operation is illustrated in Figs. 9 and 10 wherein a tank 55 contains a quantity of solution 56. The shell and filter mass is deposited in the tank so that the batt is entirely submerged as indicated in Fig. 9. Then the entire structure is lifted from the tank as indicated in Fig. 10. It will be noted that the mass is higher or thicker from top to bottom before being dipped than it is after being dipped. The speed with which the shell is withdrawn from the plastic bath will gauge the thickness of the filter element. Usually a gentle dipping is preferred, and the filter element will shrink to the proportion indicated in Figs. 9 and 10 by virtue of a relatively gentle withdrawal from the plastic bath. Upon withdrawal from the bath, the entire unit is permitted to drain free of excess plastic through the holes 49 in the bottom of the shell, and then it is subjected to a drying operation, either air dried which of course requires the most time, or it may be subjected to a heat treatment as by passing it through an oven, as above explained, to hasten the drying time. When dry, the individual strands of hair are bonded to each other at random and at intervals, providing a filter mass or element that will not compact during use, that will not channel during use, that is resilient, and of substantially uniform density throughout. Such an element on actual test with U. S. Army iine dust has proven of greater efficiency than the cattle tail hair filter element used heretofore.

In Figs. 11 and 12 I have indicated, somewhat diagrammatically, how a resilient batt of indefinite length may be equivalent short animal hair. In this construction the diagrammatically illustrated apparatus includes a pair of pulleys t! and 58 around which an endless conveyor is trained. This conveyor includes a plurality of pivotal and overlapping bottom plates E9, and pivotal and overlapping upstanding side plates to on each side oi the conveyor. Thus, the structure is channelshaped in cross section, but sufficiently flexible to pass around the pulleys 5'! and til. is deposited continuously on the conveyor from the discharge spout 3! of the machine above described. Instead of measuring out predetermined quantities or" the hair for each individual filter element, as was above described, the hair is merely continuously placed between the belts so that a continuous and even discharge of hair is acquired through the spout 35. As the deposited hair travels along on the conveyor an endless belt 65 mounted upon a series of pulleys 62 presses the conveyor and hair thereon into a tank 53 containing a bath of plastic bonding solution 65. The conveyor then carries the now wet mass of hair through a drying oven diagrammatically indicated at 65. The finished batt made from hog hair or The hair 8 66 emanates from the drying oven, and a section of this batt is illustrated in Fig. 12. The batt is separated from the conveyor in any suitable manner such as by a scraper element 61.

The completed batt may be used for many and various purposes. The batt is self-sustaining, resilient, and of substantially uniform density, so that it may either be used as a filter element or as a cushion. Sections may be removed from the batt in any desired shape and used as a filter medium in air conditioning systems, air purifying systems and similar locations. Various other uses as will be apparent to one skilled in the art may be made of such a batt of material.

From the foregoing it is apparent that I have provided a novel method for making a resilient filter element or batt of bonded short animal hair, especially hog hair. The method thereby provides a new use for a material, hog hair, that heretofore had little use as a filter element and was limited in its capacity for any use. Further, the method may be practiced with ease and economy, resulting in the production of a superior product.

It will, of course, be understood that the procedure may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

We claim as our invention:

1. The method of making a filter unit for an automotive cleaner, including the steps of separating strands of short animal hair and depositing them at random in a filter holding shell to form a mass of substantially uniform density in the shell, then dipping the shell and its contents in a bath of plastic bonding agent to bond the hair strands together and to the shell, and controlling the compactness of the hair mass by the speed of withdrawal from the bath.

2. The method of making a filter unit for an automotive air cleane including the steps of separating strands of short animal substantially dry hair and depositing them at random in a filter holding shell having a loose protective screen in the bottom thereof to form a mass of substantially uniform density in the shell over the screen, spinning the shell during the deposition of hair therein to insure uniform distribution of hair, dipping the shell and its contents in a bath of plastic bonding agent, and drying the shell and its contents to bond the hair strands together at points of contact and to the shell and screen.

3. The method of making an air cleaner filter unit, including the steps or" distributing a quantity'of substantially dry hog hair in its normal shape uniformly in a filter holding shell, dipping the shell and hair content in a'neoprene latex bath, and drying the shell and hair content to bind the hair strands together and to the shell.

l. The method of making a filter unit for an automotive air cleaner, including the steps of depositing short animal hairs in their natural shape at random in a filter holding shell, applying an oil resistant plastic bonding agent to the hairs and shell to bond the hairs together at points or" contact and to the shell, drying the bonding agent.

(Reterences on following pa e) References Cited in the file of this patent Number UNITED STATES PATENTS Name Date Yule et a1. July 11, 1882 5 Waibel Oct. 4, 1892 Weinheim June 3, 1919 Wescott Oct. 25, 1927 Weber et a1 Apr. 25, 1933 Kollek Sept. 15, 1936 10 Number Number Name Date Collins June 30, 1942 Manning Nov. 26, 1946 'I'alalay Dec. 7, 1948 FOREIGN PATENTS Country Date France Apr. 23, 1934 France July 30, 1934 

